JPH098929A - Tele control system - Google Patents

Abstract

(57) [Abstract] [Purpose] If communication between the terminal device and the center device that perform communication via the terminal network control device is not possible, switch to backup. A communication control unit 12 that controls a communication destination switching unit 11 according to the content of a received signal and a reception interval is provided, and a first terminal network control device 2A transmits and receives information to and from a meter reading meter 1. The second terminal network control device 2B includes a terminal communication unit 21 and a first communication relay unit 22 that relays transmission and reception of information between the center device 3 and the first terminal communication unit 21 via a telephone line. A second terminal communication unit 23 that transmits and receives information to and from the meter reading meter 1, and a second terminal that relays transmission and reception of information between the center device 3 and the terminal communication unit 23 via a telephone line.
Communication relay unit 24.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information communication system in which a terminal device having a communication function is connected to a center device via a telephone line for communication by a terminal network control device, and particularly, a meter reading meter is provided in the terminal network control device. The present invention relates to a telecontrol system such as an automatic meter reading system which is connected to.

[0002]

2. Description of the Related Art FIG. 5 is a block diagram of a conventional automatic meter reading system which is one of the telecontrol systems. In the figure, 1 is a meter-reading meter such as a gas meter in a customer's home as a terminal device, which stores and transmits the meter-reading value, which is the usage amount of a supply source of gas, water, electricity, etc., as device information and supplies it by a cutoff mechanism It controls the shutoff of the source. Two
Is a terminal network control device, which is usually installed on the outer wall of each house of a customer's home, sends a signal from the meter reading meter 1 to a telephone line, transmits a signal from the telephone line to the meter reading meter 1, Controls such as line disconnection. A center device 3 is installed in a management center or the like for managing the meter reading values and the like, and receives the meter reading values via a telephone line and controls the meter reading meter 1 and the terminal network control device 2. Further, generally, one meter-reading meter 1 and one terminal network control device 2 are installed in each customer's home, and the first meter-reading meter 1A corresponds to each other in a one-to-one correspondence via the first terminal network control device 2A. The second meter reading meter 1B of the adjacent house communicates with the center device 3 via the second terminal network control device 2B.

A procedure of meter reading by the conventional automatic meter reading system configured as described above will be described below with reference to FIG.

(1) The operator performs an operation for making a meter reading request to the first meter meter 1A in the center device 3. Alternatively, the application program inside the center device 3 executes a command for making a meter reading request to the first meter reading meter 1A described therein, whereby the first meter connected to the first meter reading meter 1A is connected. Terminal network control device 2A
To the telephone via a telephone line. As a connection method, a method using an ordinary public telephone network service or a method using a no ringing communication service is used.

(2) The center device 3 transmits a meter reading request signal when connected to the first terminal network control device 2A. Upon receiving the meter-reading request signal, the first terminal network control unit 2A sends this to the first meter-reading meter 1A.

(3) When the first meter-reading meter 1A receives the meter-reading request signal, it sends the stored meter-reading value. The first terminal network control device 2A transmits the data received from the first meter reading meter 1A (in this case, the meter reading value) to the center device 3 via the telephone line.

(4) If the received meter reading value is normal data, the center device 3 sends an end signal and disconnects the line. Upon receiving the end signal, the first terminal network control device 2A sends the end signal to the first meter reading meter 1A. The 1st meter-reading meter 1A will complete | finish communication normally, if an end signal is received within the predetermined time.

In the meter reading of the second meter reading meter 1B, the center device 3 via the second terminal network control device 2B is operated in the same procedure.
It is carried out by communication with.

The fact that the first meter-reading meter 1A does not receive a signal within the predetermined time of the above procedure (4)
This may occur due to a failure of the first terminal network control device 2A or a disconnection of the telephone line. As a countermeasure against such a line failure, a method is widely used as a backup method for data communication, in which a backup public line is prepared in advance in addition to the line used for normal communication, and the line is switched to a backup line only when a line error occurs. It is used (Japanese Patent Publication Sho 63-
193653).

The meter-reading meter also detects an abnormality such as a gas leak and sends an emergency notification such as a gas leak notification to the center device through the connected terminal network control device.

Further, the meter meter is connected to a gas leak alarm device or a water heater as an equipment device to receive gas leak information and device information such as usage status and failure information, thereby storing the device state. The power supply is cut off by a shutoff mechanism, and this information is sent to the center device via the terminal network control device.

[0012]

However, in the above-mentioned conventional configuration, since there is generally only one telephone line in the home, communication with the meter-reading meter connected to the terminal network control device is possible due to a failure of the terminal network control device or the like. If it disappears, it will not be possible to make an emergency call such as a meter reading from the center device or a gas leak from the meter reading to the center device, and a backup line will be prepared as a spare as seen in Japanese Patent Publication No. 63-193653. There was a problem that extra cost would be required to do so.

In general, a meter reading meter and a terminal network controller for relaying the communication are installed in each house one by one, and a meter reading meter is connected to the terminal network controller of the adjacent house for communication. In order to do so, it was necessary to wire between the houses.

Further, since the terminal network control device normally communicates only with its own meter-reading meter, there is no method of notifying the center device when the meter-reading meter becomes incommunicable.

Further, when a facility device such as a gas leak alarm or a water heater connected to a meter reading meter which is a terminal device issues a gas leak notification or failure notification via the meter reading meter, There has been a problem that an emergency call to the center device cannot be made or is delayed due to a failure of the communication function or a delay caused by communication relay.

In order to solve the above-mentioned first problem, the present invention solves the above-mentioned first problem, and even if communication between the terminal device and the center device via one terminal network control device becomes impossible, the meter reading from the center device and the transmission to the center device are performed. It is intended to provide a telecontrol system capable of making an emergency call such as a gas leak.

Further, in order to solve the second problem, it is another object of the present invention to provide a telecontrol system capable of easily connecting a terminal device to a terminal network control device of a neighboring house for communication.

Further, in order to solve the third problem, it is an object of the present invention to provide a telecontrol system capable of notifying the center device when it cannot communicate with the center device via the terminal network control device to which the terminal device is connected. It is intended.

Further, in order to solve the fourth problem, it is an object of the present invention to provide a telecontrol system capable of notifying an urgent message from a facility device to a center device without going through a terminal device. is there.

[0020]

According to the present invention, in order to achieve the first object, (1) a terminal device sends or receives information to or from a first terminal network control device or a second terminal network control device. The first terminal network includes a communication destination switching unit that switches between devices to transmit and receive information, and a communication control unit that generates transmission information, analyzes received information, and controls the communication destination switching unit. A control device relays transmission and reception of information between a center device and the first terminal communication unit via a telephone line and a first terminal communication unit that transmits and receives information to and from the terminal device.
And a communication relay unit of the second terminal network control device,
A second terminal communication unit that transmits and receives information to and from the terminal device, and a second communication relay unit that relays transmission and reception of information between the center device and the terminal communication unit via a telephone line.

In order to achieve the second object,
(2) The communication destination switching unit of the terminal device has a function of wirelessly transmitting and receiving a signal when the communication destination is switched to the second terminal network control device, and the second destination network control device of the second terminal network control device is provided. The communication relay unit has a function of wirelessly transmitting and receiving a signal to and from the terminal device.

In order to achieve the third object,
(3) The communication destination switching unit of the terminal device has a function of wirelessly transmitting a link request signal when starting communication with the second terminal network control device, and the second terminal network control device of the second terminal network control device is provided. The terminal communication unit has a function of wirelessly receiving a link request signal from the terminal device, performing a link connection with the terminal device, and transmitting and receiving a signal.

Alternatively, (4) the first terminal network controller is
A first terminal communication unit that transmits and receives information to and from a terminal device, a first wireless communication unit that wirelessly transmits and receives information to and from a second terminal network control device, the center device and the terminal via a telephone line. A first communication relay unit for relaying transmission / reception of information to / from a communication unit or a first wireless communication unit, wherein the second terminal network control device and the first terminal network control device wirelessly exchange information. A second wireless communication unit that transmits and receives, a second terminal communication unit that transmits and receives information to and from the terminal device, and the center device and the second terminal communication unit or the second wireless communication via a telephone line. And a second communication relay unit for relaying transmission / reception of information to / from the unit.

In order to achieve the fourth object,
(5) A terminal network control device that connects to the terminal device and also connects to the center device via a telephone line to relay communication between the terminal device and the center device, a device control unit that controls the device, and An equipment communication device is provided which is connected to a device control unit and which switches a destination of information transmission and reception between the terminal device and the terminal network control device according to the content of the transmission information and transmits and receives a signal.

[0025]

According to the telecontrol system of the present invention, the communication control unit of the terminal device controls the communication destination switching unit to switch the communication destination to the second terminal network control device according to the first configuration described above. As a result, the terminal device communicates with the center device via the second terminal network control device.

Further, according to the second configuration, the terminal device wirelessly communicates with the second terminal network control device, thereby communicating with the center device via the second terminal network control device. .

According to the third configuration, when the communication destination switching unit of the terminal device outputs the link request signal to the second terminal network control device, the second terminal network control device
The communication between the center device and the terminal device is relayed by connecting a link with the terminal device through a telephone line.

Further, according to the fourth configuration, the first wireless communication unit communicates with the first terminal network control device and the second terminal network control device via the second wireless communication unit. , The signal from the first terminal network controller is transmitted to the center apparatus via the second terminal network controller.

Further, according to the fifth configuration, the device communication control unit of the terminal device switches the transmission destination to the terminal device or the terminal network control device according to the content of the transmission information for communication.

[0030]

1 is a block diagram of an automatic meter reading system as an example of a telecontrol system according to a first embodiment of the present invention.

As shown in the figure, the difference from the conventional example of FIG. 5 is that the meter-reading meter 1 is also connected to the second terminal network control unit 2B. In the meter-reading meter 1, 11 is a communication destination switching unit, which transmits / receives information by switching the transmission / reception destination of information to the first terminal network control device 2A or the second terminal network control device 2B, and 12 is a communication control unit. , The transmission information is generated, the reception information is analyzed, and the communication destination switching unit 11 is controlled according to the content of the reception information and the interval of the reception signal.
A meter reading control unit 3 measures the flow rate and cuts off the supply source. Further, in the first terminal network control device 2A, 21 is a first terminal communication unit, which transmits and receives information to and from the terminal device 1, and 22 is a first communication relay unit, which is a center device 3 via a telephone line. In order to relay information with the first terminal communication unit 21, signal modulation / demodulation processing and telephone line connection / disconnection processing are performed. Furthermore, in the second terminal network control device 2B, 23
Is a second terminal communication unit for transmitting / receiving information to / from the terminal device 1, and 24 is a second communication relay unit for relaying information between the center device 3 and the second terminal communication unit 23 via a telephone line. In order to do so, signal modulation / demodulation processing and telephone line connection / disconnection processing are performed.

Next, the operation of the first embodiment will be described in detail. Regarding the communication between the terminal device 1 and the center device 3 in the normal state, the meter reading from the center device 3 is relayed by the first terminal network control device 2A in the following procedure as in the conventional example.

(1) The operator performs an operation for making a meter reading request to the first meter meter 1A in the center device 3. Alternatively, the application program in the center device 3 executes a command for making a meter reading request to the first meter reading meter 1A described therein, thereby making a telephone line connection to the first terminal network control device 2A. Make a connection request via.

(2) The first communication relay unit 22 of the first terminal network controller 2A establishes a connection in response to a connection request from the center apparatus 3. As a connection method, a method using an ordinary public telephone network service or a method using a no ringing communication service is used.

(3) The center device 3 transmits a meter reading request signal when connected to the first terminal network control device 2A.

(4) Upon receipt of the meter-reading request signal, the first communication relay section 22 sends it to the first meter-reading meter 1A via the first terminal communication section 21.

(5) When the communication control unit 12 of the first meter-reading meter 1A receives a meter-reading request signal from the first terminal network controller 2A via the communication destination switching unit 11, the meter-reading control unit 13 reads the meter-reading value. Is read and generated as transmission information, and the meter reading value is sent to the first terminal network control unit 2A via the communication destination switching unit 11.

(6) The first terminal network control device 2A uses the first
The meter reading value received from the first meter reading meter 1A via the terminal communication unit 21 is sent to the telephone line by the first communication relay unit 22 to notify the center device 3.

(7) If the received meter reading value is normal data, the center device 3 sends an end signal and disconnects the line.

(8) Upon receipt of the end signal, the first terminal network control device 2A sends this to the first meter-reading meter 1A, similarly to the meter-reading request signal.

(9) The first meter-reading meter 1A normally terminates the communication when it receives the termination signal within a predetermined time.

However, when the received signal is abnormal or the end signal is not received within a predetermined time, the communication control unit 12 controls the communication destination switching unit 11 to set the communication destination to the second terminal network control device. Switch to 2B. After that, the meter-reading meter 1 communicates with the center device 3 via the second terminal network control device 2A and reports that the communication with the first terminal network control device 2A is abnormal. In addition, the center device 3 performs meter reading by communicating with the meter reading meter 1 via the second terminal network control device 2B until the first terminal network control device 2A operates normally.

As described above, in the automatic meter-reading system of this embodiment, the communication relay destination of the meter-reading meter is switched to the second terminal network control device, whereby the first terminal network control device breaks down or the telephone line is disconnected. It is possible to make meter readings and reports even at times.

FIG. 2 is a block diagram of the automatic meter-reading system in the second embodiment of the present invention. The difference between the present embodiment and the first embodiment is that the meter reading meter 1 is the second terminal network control device 2
B is that it is not connected by wire. In the meter-reading meter 1, the communication destination switching unit 11 sends a link request signal at the time of starting communication with the second terminal network control device 2B and is linked to the second terminal network control device 2B. A second terminal network control device 2B having a function of performing wireless communication
The second terminal communication unit 23 has a function of receiving a link request signal from the terminal device 1 to establish a link connection with the terminal device 1 and perform wireless communication with the terminal device 1.

Next, the operation of the second embodiment will be described. In normal times, it is exactly the same as the conventional example. However, meter reading meter 1
When the communication control unit 12 does not receive the end signal within a predetermined time, the process is performed according to the following procedure.

(1) The communication control unit 12 controls the communication destination switching unit 11 to switch the communication destination to the second terminal network control device 2B.

(2) The communication control unit 12 generates an abnormality notification signal to notify the communication abnormality of the first terminal network control device 2A and sends it to the communication destination switching unit 11.

(3) The communication destination switching unit 11 sends a link connection request signal to the second terminal network control device 2B because the communication with the second terminal network control device 2B is started.

(4) Upon receiving the link connection request signal from the terminal device 1, the second terminal communication unit 23 of the second terminal network control device 2B establishes a link connection with the terminal device 1.

(5) When the link with the second terminal network control unit 2B is connected, the communication destination switching unit 11 sends an abnormality notification signal to the center unit 3 via the second terminal network control unit 2B.
Send to

(6) The center device 3 detects the communication abnormality of the first terminal network control device 2A by receiving the abnormality notification signal from the second terminal network control device 2B via the telephone line.

Further, the center device 3 connects to the second terminal network control device 2B through the telephone line until it is notified that the first terminal network control device 2A operates normally, and further, the second terminal network control device 2B. The meter reading is performed by communicating with the meter reading meter 1 via the terminal network control device 2B.

As described above, in the automatic meter-reading system of this embodiment, since the meter-reading meter and the second terminal network control device are wirelessly connected to each other, no wiring is required, and the meter-reading meter is connected to the second terminal network. A communication abnormality can be reported to the center device via the control device.

FIG. 3 is a block diagram of the automatic meter-reading system in the third embodiment of the present invention. The difference of the present embodiment from the second embodiment is that the first terminal network control device 2A transmits / receives information to / from the second terminal network control device 2B wirelessly.
Wireless communication unit 25, and when the first terminal communication unit 21 starts communication with the second meter-reading meter 1B, it sends a link request signal to perform communication or a signal with the first meter-reading meter. The second terminal network control unit 2B includes a second wireless communication unit 26 that wirelessly transmits and receives information to and from the first terminal network control device 2A. When 23 starts communication with the first meter-reading meter 1A, it sends a link request signal to perform communication, and
The meter reading meter 1A has a function of transmitting and receiving a signal to and from the terminal device 1B of
Has a function of receiving a link request signal from the second terminal network control device 2B, connecting a link, and transmitting / receiving a signal. In the meter meter 1B, the second communication destination switching unit 11B is configured to It has a function of receiving a link request signal from the terminal network control device 2A, connecting a link, and transmitting / receiving a signal.

Next, the operation of the third embodiment will be described. The normal operation is exactly the same as the conventional example. However, when the first terminal network control device 2A cannot communicate with the center device 3 due to disconnection of a telephone line or cannot communicate with the terminal device 1A, the following procedure is performed. .

(1) When the communication relay unit 22 of the first terminal network control device 2A cannot communicate with the center device 3 or cannot communicate with the terminal device 1A via the terminal communication unit 21, An abnormality notification signal is transmitted via the wireless communication unit 25 of No. 1.

(2) When the wireless communication unit 26 of the second terminal network control device 2B receives the abnormality notification signal from the first terminal network control device 2A, it sends it via the second communication relay unit 24. Send to the center device.

(3) When the center device 3 receives the abnormality notification signal from the first terminal network controller 2B, it recognizes that an abnormality has occurred in the communication with the first terminal device 1A.

(4) The center device 3 is the first terminal device 1
When the meter reading of A is performed, the first terminal device is connected to the second terminal network control device 2B via a telephone line until the first terminal network control device 2A is notified that it operates normally. 1
Send the meter reading request signal of A.

(5) The second communication relay section 24 of the second terminal network control device 2B includes the center device 3 to the first terminal device 1
When the meter-reading request signal for A is received, the meter-reading is performed by connecting the wireless link with the meter-reading meter 1A through the second terminal communication unit 23 and performing communication.

Meter reading meter 1B and second terminal network controller 2
Similarly, when an abnormality occurs in the communication with the center apparatus 3 via B, the center apparatus 3 similarly recognizes by the notification signal from the first terminal network control apparatus 2A, and the first terminal network control apparatus 2
The meter reading of the second terminal device 1B is performed via A.

In the case of the first and second embodiments as well,
It is conceivable that the second terminal network control device is connected to the second terminal device 1B to have the same configuration as that of the third embodiment.

In the above-described embodiments, the relationship between the first terminal network control device and the second terminal network control device connected to the first meter-reading meter has been shown. If there is a communication error in the network control device, communication with the center device is performed via the second terminal network control device, and if there is also communication error in the second terminal network control device, the communication is performed via the third terminal network control device. In this way, even if there are two or more switching destinations by setting the priority of communication destinations in the event of an abnormality, the abnormality notification and meter reading can be performed in the same procedure.

As described above, in the automatic meter-reading system of this embodiment, the second terminal network control device notifies the center device of a communication abnormality with the first terminal device via the first terminal network control device. be able to.

FIG. 4 is a block diagram of the telecontrol system in the fourth embodiment of the present invention.

In the figure, reference numeral 4 denotes a gas appliance as a facility appliance, which has a function of transmitting its operating condition and controlling its operation by a received signal. 41 is a device communication control unit,
It receives a signal from the meter-reading meter 1 or the terminal network control device 2, transmits a device state or the like to the meter-reading meter 1, or sends an abnormality notification to the terminal network control device 2. Reference numeral 42 denotes an equipment control unit, which performs the original operation of the gas equipment, and the equipment communication control unit 41.
The device is controlled according to a signal from the device, or the device status is sent to the device communication control unit 41. The communication control unit 12 of the meter reading meter 1 not only relays communication between the meter reading control unit 13 and the terminal network control device 2, but also sends and receives signals to and from the gas equipment 4. Further, the terminal communication unit 21 of the terminal network control device 2 not only transmits and receives signals to and from the meter meter 1, but also transmits and receives signals to and from the gas device 4.

Next, the operation of the fourth embodiment will be described. The meter reading from the center device 3 to the meter reading meter 1 and the notification from the meter reading meter 1 to the center device 3 are performed in the same procedure as in the conventional example.

The signal transmission from the gas equipment 4 is performed as follows. The equipment control unit 42 of the gas equipment 4 sends an equipment operation status signal to the equipment communication control unit 41 when the operation state of the equipment changes or at regular intervals, and when an abnormality such as equipment failure occurs, an equipment abnormality signal is sent to the equipment communication. It is sent to the control unit 41.
The device communication control part 41 will transmit this to the meter-reading meter 1, if an operating condition signal is received. Communication control unit 1 of meter reading meter 1
2 receives an operation status signal from the gas equipment 4 and judges whether or not there is an abnormality in the gas equipment 4 and controls the shutoff of the supply source by the meter reading control unit 13 or transmits an abnormality notification signal to the terminal network control device 2. I do. Upon receiving the device abnormality signal from the device control unit 42, the device communication control unit 41 transmits this to the terminal network control device 2. The terminal communication unit 21 of the terminal network control device 2
Receives an abnormality notification signal from the meter reading meter 1 or gas equipment 4
When the device abnormality signal from the device is received, the signal is transmitted to the center device 3 via the communication relay unit 22. Further, the center device 3 directly communicates with the gas device 4 via the terminal network control device 2 to read or control detailed information of the gas device 4.

As described above, in the telecontrol system of the present embodiment, it is possible to directly notify the center device from the gas device via the terminal network control device of the device error.

[0070]

The telecontrol system of the present invention is
According to the first configuration, even if the terminal device cannot communicate with the center device via the first terminal network control device, the second device
By performing communication via the terminal network control device, it is possible to perform meter reading from the center device and report from the terminal device, so the possibility that meter reading becomes impossible and gas leak alarm cannot be reported is reduced. It is very effective for maintenance and safety improvement.

Further, according to the second configuration, it is possible to wirelessly communicate between the second terminal network control device and the terminal device.
It becomes possible to install the terminal network control device and the second terminal network control device at a remote place such as a house.

Further, according to the third configuration, since the terminal device requests the second terminal network control device for link connection, the second terminal network control device can be connected to the terminal network control device to perform communication. The terminal device can notify the center device via the second terminal network control device that the terminal device cannot communicate via the first terminal network control device, and the center device can notify the telephone line or the first terminal. It becomes possible to promptly recognize the abnormality of the network control device.

Further, according to the fourth configuration, since it is possible to wirelessly communicate between the first terminal network control device and the second terminal network control device, the communication abnormality of one terminal network control device can be prevented from the other. By transmitting to the terminal network control device, the center device can be notified of the communication abnormality, and the center device can quickly recognize the abnormality of the telephone line or the terminal device.

Further, according to the fifth configuration, since the terminal network control device can notify the center device of the failure notification of the facility device without passing through the terminal device, the center device can quickly recognize the abnormality of the facility device. .

[Brief description of drawings]

FIG. 1 is a block configuration diagram of a telecontrol system according to a first embodiment of the present invention.

FIG. 2 is a block configuration diagram of a telecontrol system according to a second embodiment of the present invention.

FIG. 3 is a block configuration diagram of a telecontrol system according to a third embodiment of the present invention.

FIG. 4 is a block configuration diagram of a telecontrol system according to a fourth embodiment of the present invention.

FIG. 5 is a block diagram of a conventional telecontrol system.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Meter-reading meter (terminal device) 2 Terminal network control device 3 Center terminal 4 Gas equipment (facility equipment) 11 Destination switching part 12 Communication control part 13 Meter-reading control part 21 1st terminal communication part 22 1st communication relay part 23 Second terminal communication unit 24 Second communication relay unit 25 First wireless communication unit 26 Second wireless communication unit 41 Device communication control unit 42 Device control unit

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Shiro Honma 1006 Kazuma Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd.

Claims (5)

[Claims] 1. A terminal device for inputting / outputting information, a center device for controlling the terminal device, and a terminal network control device connected to the terminal device for relaying communication with the center device via a telephone line. In the configured tele-control system, the terminal device switches a destination of information transmission / reception to a first terminal network control device or a second terminal network control device, and transmits / receives information, and a transmission information And a communication control unit that analyzes received information and controls the communication destination switching unit, and the first terminal network control device,
A first terminal communication unit that transmits and receives information to and from the terminal device, and a first communication relay unit that relays transmission and reception of information between the center device and the first terminal communication unit via a telephone line. The second terminal network control device includes a second terminal communication unit that transmits and receives information to and from the terminal device, and relays transmission and reception of information between the center device and the terminal communication unit via a telephone line. A telecontrol system including a second communication relay unit. 2. The second communication relay unit wirelessly transmits and receives to and from the terminal device when the communication destination switching unit of the terminal device switches the communication destination to the second terminal network control device. Tele control system. 3. When the communication destination switching unit of the terminal device starts communication with the second terminal network control device, the second terminal communication unit wirelessly receives and transmits / receives a link request signal from the terminal device. The telecontrol system according to claim 1, wherein 4. The first terminal network controller is provided with a first wireless communication unit connected to the first communication relay unit for performing wireless transmission and reception with the second terminal network controller, and the second terminal network controller is provided. The telecontrol system according to claim 1, wherein the terminal network control device includes a second terminal communication unit which is connected to a second communication relay unit and wirelessly transmits and receives to and from the first terminal network control device. 5. A terminal network control device which is connected to a terminal device and which is connected to a center device via a telephone line for relaying, a device control unit for controlling devices, and a destination of information connected to the device control unit. A telecontrol system comprising equipment equipment including a device communication control unit for transmitting and receiving signals by switching between the terminal device and the terminal network control device.